1. Field of the Invention
The present invention is directed to providing new and improved direct positive radiation recording photosensitive photographic elements.
2. Description of the Prior Art
As is known in the prior art, photographic silver halide elements may be constituted which are adapted to provide, upon photoexposure and processing, direct positive image formation, that is, image formation in terms of the unexposed areas of the element as a function of the point-to-point degree of the elements' exposure to incident electromagnetic radiation actinic to the silver halide crystals constituting such elements. Specifically, the constitution of direct positive silver halide elements adapted to provide the requisite reversal image formation, as a function of photoexposure and chemical processing, is disclosed in substantial detail in a plurality of United States and foreign patents including among others U.S. Pat. Nos. 2,592,250; 3,206,313; 3,317,322; 3,364,026; 3,367,778; 3,501,305; 3,501,306; 3,501,307; 3,501,309; 3,501,310; 3,501,311; 3,501,312; 3,505,070; 3,537,858; and the like.
In general, the aforementioned direct positive silver halide elements comprise a particulate dispersion of substantially uniformly fogged silver halide crystals or grains which in particularly preferred situations may comprise uniformly fogged silver halide grains comprising a central core of silver halide containing centers which promote deposition of photolytic silver and an outer shell covering the core comprising fogged silver halide that is adapted to be rapidly reduced to silver absent photoexposure; the latter structures being described in further detail in U.S. patents such as aforementioned U.S. Pat. Nos. 3,206,313; 3,317,322; 3,367,778; 3,537,858; and the like.